Effects of Cooking Methods on Antioxidant Capacity of Sweet Potato Stems and Leaves
To explore the effects of different cooking methods on the antioxidant capacity of sweet potato stems and leaves,with the content of total phenols,flavonoids and DPPH·scavenging capacity as the evaluation indexes of antioxidant capacity,three different cooking methods,namely blanching,oil stir-frying and microwave,are used to treat sweet potato stems and leaves,and the changes of the antioxidant capacity under different cooking methods and conditions are determined.The results show that the antioxidant capacity of sweet potato stems and leaves is negatively correlated with blanching time and blanching temperature,and the decreasing trend of the antioxidant capacity is more significant(P<0.05)when the temperature is higher than 70 ℃;the antioxidant capacity of sweet potato stems and leaves is positively regulated by oil stir-frying time and the addition amount of oil;the antioxidant capacity shows a trend of increasing firstly and then decreasing with the extension of microwave time,and it is the strongest at 3 min.When the microwave power increases,the content of flavonoids and total phenols in sweet potato stems and leaves decreases firstly and then increases,and the difference is significant(P<0.05),while the DPPH·scavenging rate shows a negative correlation trend.
cooking methodsweet potato stems and leavesantioxidant capacity